CN1053063C

CN1053063C - Method for passivating III-V family semiconductor surface by using sulfur chloride

Info

Publication number: CN1053063C
Application number: CN94112024A
Authority: CN
Inventors: 侯晓远; 李喆深; 蔡卫中; 王为; 丁训民; 董国胜; 王迅
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 1994-01-18
Filing date: 1994-01-18
Publication date: 2000-05-31
Anticipated expiration: 2014-01-18
Also published as: CN1105780A

Abstract

The present invention relates to a method for passivation semiconductor material of group III-V and the surface of a device by using sulfur chloride. The existing passivation method has the defects of long time and need of temperature control. The present invention uses the sulfur chloride to treat the semiconductor material of group III-V and the device only by that after a semiconductor is pre-cleaned, and the semiconductor is put into a sulfur chloride solution for several seconds to decade seconds at room temperature, is washed by anhydrous organic solvents, acetone and water, and then is weathered by nitrogen after being taken out. The method has the advantages of implementation at room temperature, simple condition, short treating time and compact technology, and can be used as surface passivation technique for the semiconductor of group III-V such as semiconductor material of GaAs, InP, InSb, etc. and devices.

Description

The method of a kind of sulfur passivation III-V family semiconductor material surface

The surface passivation that the present invention relates to GaAs material and device is handled.

The semiconductor silicon device of present more use, its SiO ₂Be a kind of very desirable passivating film, Si/SiO ₂There are low-down interface state density and good chemical stability in the interface.People once attempted to make similar Si/SiO on other semi-conducting material or device ₂The interface, but all failed, therefore begin people from the eighties to recognize that it is impracticable that compound semiconductor is used from the body oxide passivation layer.1987, people such as Sandroff proposed the sulfur passivation method on GaAs surface.They use Na ₂S9H ₂O solution soaks the GaAs material, and the material surface recombination velocity is significantly reduced, and obtains intensity from photoluminescence spectrum and increases two orders of magnitude.Human (NH is arranged later on ₄) ₂S solution soaks and also has similar effect.This sulfur passivation method can be removed the oxide of gallium arsenide surface and stay one deck sulphur atom and be combined with arsenic or gallium, and the dangling bonds of saturated GaAs greatly reduce surface density of states and recombination-rate surface.The shortcoming of this processing method is that the processing procedure time is oversize, need tens hours under the general room temperature, even in the time of 60 ℃, passivating process also needs 30～60 minutes, and because the effect of the aqueous solution, gallium arsenide surface after the processing still aerobic exists, and oxygen is easy to destroy the passivation of sulphur to the surface.Therefore seeking sulfur passivation processing method fast and effectively, particularly reduce oxygen residual on the surface as far as possible, is to need one of key issue that solves during present sulfur passivation is handled.Processing method particularly reduces oxygen residual on the surface as far as possible, is to need one of key issue that solves during present sulfur passivation is handled.

The objective of the invention is to seek the method for a kind of simple III-V family semi-conducting material fast and device surface sulfur passivation.

The present invention for semi-conducting material routinely chemical treatment method do prerinse earlier, put it under the room temperature then and soaked in the sulfur chloride solution 3～50 seconds, with anhydrous organic solvent, acetone and water flushing, dry up with nitrogen more immediately; If processing semiconductor device then room temperature with the anhydrous organic solvent flushing, will be used ultrasonic 30～60 seconds of acetone immediately again with after the sulfur chloride solution-treated, last nitrogen dries up.

Usually the sulfur chloride solution of usefulness has Sulphur Monochloride and sulphur dichloride.

Semi-conducting material and device are handled two steps usually, the first step is preliminary treatment, preprocess method and conventional chemical processing method are similar among the present invention, i.e. first ultrasonic dewax about ten minutes in trichloroethylene, after drying up, taking-up use acetone, ethanolic solution about ultrasonic ten minutes again, rinse well with deionized water at last, nitrogen dries up and gets final product.If pure sulfur chloride during with the sulfur chloride solution-treated, then the processing time can lack, and the time has been grown and can cause that sample is scared; If the sulfur chloride with dilution is handled, but processing time proper extension then, and the proper extension time is convenient to operation control.Will be after the processing immediately with the anhydrous organic solvent flushing, anhydrous organic solvent commonly used has carbon tetrachloride, chloroform etc.Handling semi-conducting material can be with acetone and water flushing, must be earlier with acetone water flushing then, otherwise water easily with sulfur chloride in reaction of Salmon-Saxl generation oxide.When handling semiconductor device, handle, dry up with using acetone ultrasonic after the anhydrous organic solvent flushing, taking out with nitrogen again with sulfur chloride.Semiconductor device is handled through sulfur chloride, must be ultrasonic after the anhydrous organic solvent flushing through acetone, otherwise dirt does not thoroughly clean out meeting continuation corrosion device surface in the device.

Handle the time of semi-conducting material or device if wish the proper extension sulfur chloride, sulfur chloride can be diluted with carbon tetrachloride, chloroform equal solvent.

The present invention handles semi-conducting material or device with sulfur chloride, and the more of usefulness is sulfur monochloride or sulfur dichloride.

The inventive method can be handled III-V family semiconductor, example: GaAs, InP, InSb etc.

Handle III-V family's semi-conducting material and device with the inventive method, at room temperature only need to reach passivation effect several seconds, than using (NH ₄) ₂S or Na ₂S9H ₂The O treatment effeciency is much higher.If with diluting also may command passivation rate of sulfur chloride solution.With GaAs is example, and from the passivation effect of luminescence generated by light (PL) spectrum sulfur chloride, the strength ratio autoxidation gallium arsenide surface of PL spectrum is wanted big two orders of magnitude.Sulfur chloride and (NH are described ₄) ₂S is the same, all GaAs material and device is had good passivation effect.If handle is sent in the vacuum with the GaAs sample after the sulfur chloride passivation, laser radiation sample one hour, PL intensity does not have any variation yet.The GaAs sample of handling through sulfur chloride records the limit that its surperficial oxygen content almost is lower than the Auger measurement from Auger electron spectroscopy (AES).If will be exposed to dozens of minutes in the atmosphere through the sample that sulfur chloride is handled, perhaps be immersed in the deionized water 40 hours, carry out the AES spectrometry again, both all do not find the increase of oxygen content.Because sulfur chloride is very effective to removing the semiconductor surface oxide, for general sulphurous water solution-treated can not be compared, therefore and the semiconductor surface of handling does not conform to oxygen, can reach the deoxidation effect of passivation again to the substrate processing means of sulfur chloride before as the semiconductor molecule beam epitaxy yet.Following table provides the different disposal method, is standard with Ga (LMN), and comparing of different elements A ES spectrum peak, GaAs surface one peak height as can be seen from the table, used S ₂Cl ₂(NH ₄) ₂The sulphur of S processing method is approximate identical with the relative intensity ratio of arsenic, gallium.Therefore, S ₂Cl ₂Processing method and (NH ₄) ₂The sulfuric horizon thickness difference that the S processing method generates is few.The sulfuric horizon that two kinds of methods generate all exists in atmosphere and reoxidizes problem, but S ₂Cl ₂It is much simple and practical that processing method is wanted.The relative intensity ratio at GaAs surfaces A ES spectrum peak

	S	O	Ga	As
	S	O	Ga	As	S ₂Cl ₂Handle	5.52	0	1	0.68
(NH ₄) ₂S handles	5.56	0.34	1	0.75	S ₂Cl ₂Handle	5.52	0	1	0.68
(NH ₄) ₂S handles	5.56	0.34	1	0.75	Be untreated	0	2.09	1	0.69

Embodiment 1:

Get the pure S of 10ml ₂Cl ₂The beaker of putting into cleaning, drying deals with liquid, with 1cm ²The GaAs (100) of size is doped to 10 of Te ¹⁷Cm ^-3The single-chip of single-sided polishing be processed material, put into the ultrasonic dewax of 10ml trichloroethylene earlier, take out after 10 minutes and dry up, the acetone of usefulness 10ml, ethanolic solution are distinguished ultrasonic 10 minutes successively again, rinse well with deionized water at last, dry up with nitrogen, sample pretreatment finishes.

Processing procedure: the tweezers with dry cleansing are clamped sample, put into pure S ₂Cl ₂5 seconds in the solution, take out immediately, with the carbon tetrachloride solvent flushing, use acetone and deionized water rinsing more successively, dry up with nitrogen at last.The light fluorescence intensity of this sample has improved two orders of magnitude after tested, and surface electron spectrum records its surface oxygen content and is lower than the Auger detection limit.Embodiment 2:

It is identical with the processing GaAs material substantially to handle the GaAs device method, just uses S ₂Cl ₂Must be ultrasonic behind the processing apparatus with acetone, dirt in the device is thoroughly removed, be earlier that the heterojunction bipolar mesa transistor of material is put into S with semiconductor device GaAlAs/GaAs ₂Cl ₂In 5 seconds, take out immediately and put into 50 milliliters CCl ₄Clean in the solution, use 50 milliliters of ultrasonic half a minute of acetone again, taking-up dries up with nitrogen.This transistorized β increases to 30 by 20 before handling after tested, and test condition is injection current I _c=0.01mA, I _b=0.01mA/ level records with JT-2 transistor npn npn graphic instrument.

Claims

1, the method for a kind of sulfur passivation III-V family semiconductor material surface, after semi-conducting material is used conventional chemical method clean, handle with sulfide then, it is characterized in that: the material room temperature is transferred 3-50 second in the sulfur chloride solution, and washing then with anhydrous organic solvent, acetone, water again, nitrogen dries up.

2, the method for a kind of sulfur passivation III-V family semiconductor device, it is characterized in that: semiconductor device by using conventional chemical method use the sulfur chloride solution-treated after cleaning under the room temperature, and again with the anhydrous organic solvent flushing, the ultrasonic 30-60 of acetone second, nitrogen dries up at last.